In many organizations, for example in industry, in large kitchens and in large hotels where many rooms need to be cleaned regularly, small containers, such as easily portable bottles, are frequently refilled with cleaning and sanitizing liquids from bulk containers held at a filling station. The dispenser is typically of the type described in EP 0868137. This describes a manually operated dispenser for dispensing measured single shots of fluid from a reservoir into a container positioned beneath the outlet. The containers being filled are typically labeled or colored in order to indicate the liquid which they should contain. There are obvious risks of errors here, that a liquid might be filled into a container for which it was not intended, particularly when many people frequently visit a filling station. Simple color coding systems, whilst helpful, do not remove the possibility of human error.
Attempts have been made to overcome this problem by electronic automated filling systems, but these tend to be very complex, involving for example the reading of bar code labels. Such systems are expensive, they require expert set-up and maintenance, and are prone to the occurrence of faults.